1. Technical Field
The present invention relates to an electric connection device interposed between a handle (steering wheel) and a steering column for an automotive vehicle, and more specifically to an electric connection device for transmitting various control signals from switches mounted on a steering wheel to a controller, for instance through the steering column.
2. Description of the Prior Art
With the advance of electronic control in the field of automotive vehicles, a number of control switches are arranged on a steering wheel (i.e., handle) of an automotive vehicle to execute various controls of the automotive vehicle. In this case, since the steering wheel is usually rotated by a few turns in both clockwise and counterclockwise directions, a flexible flat cable (FFC) having a plurality of conductive wires therein are connected between a rotary body fixed to a handle shaft and a device housing fixed to the steering column, so that electric signals of the control switches can be transmitted from the steering wheel to the other side of the automotive vehicle through the steering column. Further, when interposed between the steering wheel and the steering column, the flexible flat cable is usually housed in the device housing in a vortex state or a reversal vortex state (the rotational direction being reversed midway in the vortex state).
In the conventional electric connection device as described above, however, there exists a problem in that an abnormal sound (noise) is generated whenever the steering wheel is rotated.
The inventors have examined and studied the reasons why the above-mentioned abnormal noise is generated whenever the steering wheel is rotated in either direction, and then found out that the abnormal noise is generated due to the sliding contact between the flexible flat cable and an annular flat cable carrier at only a reversal position at which the movement direction of the flexible flat cable is reversed in the circumferential direction of the device and thereby shifted in the radial direction of the device.